Control of fluid flow using a flexible disc

ABSTRACT

Method and apparatus for the control of fluid flow using a flexible disc that is positioned in a control channel and restricted to movement along the longitudinal axis of the channel. Closure control is exercised by moving the disc into closer contact with a ring seat that is essentially self-purging of debris. Since the disc is confined to essentially longitudinal movement, distortion due to random lateral movement is avoided.

This application is a continuation-in-part of Ser. No. 235,668, filedFeb. 18, 1981, now U.S. Pat. No. 4,369,812, which is in turn acontinuation-in-part of Ser. No. 50,823, filed June 21, 1979 and nowU.S. Pat. No. 4,286,628, issued Sept. 1, 1981.

BACKGROUND OF THE INVENTION

This invention relates to flow control, and, more particularly, to thecontrol of fluid flow making use of pressure differentials.

In many situations it is necessary to control the flow of fluids, suchas liquids and gases. A common device for that purpose is known as acheck valve. It functions by the deflection of an elastomeric elementtowards a valve seat in order to prevent flow and away from the seat topermit flow.

One such device is the check valve disclosed in U.S. Pat. No. 3,889,710which issued to Julien H. Brost on June 17, 1975. It contains anelastomeric disc that is deflected towards and away from a concaveseating surface that surrounds an inlet. The disc is deliberately madesmaller than the seating surface. This is to permit reverse flow aroundthe edges of the disc.

Unfortunately, the use of a concave seating surface with a floatabledisc, i.e. one that is smaller than the seating surface, causes a numberof difficulties. In the first place a valve with a concave seatingsurface is susceptible to malfunction because inevitable particles ofdebris that become trapped between the disc and its concave seat. Oncedebris becomes trapped it tends to remain on the seat during subsequentoperations of the valve. In addition since the disc is smaller than itsseat it tends to move about with the result that different portions ofthe surface become stressed during subsequent operations. Furthermore,there is an undesirable tendency for a portion of the disc to be drawninto the associated inlet during closure operation of the valve.

Other known valves for controlling flow are those illustrated by thefollowing patents:

    ______________________________________                                        Patent No. Issued          Inventor                                           ______________________________________                                          797,739  8/1905          Meer                                               1,412,473  4/1922          Lane                                               1,506,012  8/1924          Lewis                                              2,547,377  4/1951          Juhasz                                             3,342,866  4/1966          Sanz                                               3,664,371  5/1972          Schneider                                          ______________________________________                                    

Still other known valves for controlling flow are those illustrated bythe following additional patents:

    ______________________________________                                        Patent No.  Issued          Inventor                                          ______________________________________                                        3,807,445   4/1974          McPhee                                            3,954,121   5/1976          Kardos                                            ______________________________________                                    

Accordingly, it is an object of the invention to facilitate the controlof fluid flow. A related object is to facilitate the control of fluidflow using differential pressures.

A further object of the invention is to overcome the difficultiesassociated with prior check valves. A related object is to avoid thedifficulties associated with a single disc check valves.

Still another object of the invention is to avoid the difficultiesassociated with "floatable" disc. A related object is to avoid thedifficulties associated with discs that are smaller than theirassociated seats. Another related object is to avoid the random wearpattern associated with "floatable" discs.

Yet another object of the invention is to reduce disc distortion incheck valves. A related object is to reduce the tendency for a disc tobe drawn into a flow channel and produce disc distortion.

A yet further object of the invention is to facilitate the seatingaction of a valve disc and render the valve substantially self purgingof debris, such as dirt and dust, that could otherwise interfere withthe seating operation.

SUMMARY OF THE INVENTION

In accomplishing the foregoing and related objects, the inventionprovides for the exercise of flow control using a resiliant and flexibledisc which is restricted to movement along the longitudinal axis of acontrol channel. This avoids the disadvantages of variable positionablediscs, while retaining their advantages.

In accordance with one aspect of the invention the disc is symmetricallypositioned with respect to the control channel to assure uniformperformance of the disc during opening and closure operations.

In accordance with another aspect of the invention, the disc has a ringseat with rounded, convex shoulders that facilitate seating duringinitial preloading of the disc, and facilitate the self-purging ofdebris from the seat.

In accordance with still another aspect of the invention, the entranceof the flow channel is a base depression surrounded by the ring seat.This helps assure that the disc is securely seated when the valve isfully closed.

In accordance with yet another aspect of the invention, the basedepression of the ring seat includes radial channels that limit thetendency of the disc to be drawn into the flow channel.

According to a further aspect of the invention, the control channelincludes peripheral grooves for the flow of fluid during the opencondition of the valve.

According to a still further aspect of the invention, the disc isprestressed by a member with auxiliary flow channels for accommodatingthe reverse flow of fluid through the valve. The latter channels aredesirably symmetrically, laterally and radially positioned with respectto a main flow channel.

DESCRIPTION OF THE DRAWINGS

Other aspects of the invention will become apparent after consideringseveral illustrative embodiments taken in conjunction with the drawingsin which:

FIG. 1 is a perspective view of a control valve in accordance with theinvention;

FIG. 2 is a fragmentary cross-sectional view of the control valve ofFIG. 1;

FIG. 3 is an end view of a constituent member of the control valveshowing structural channels for reverse operation and the avoidance ofcontrol disc distortion;

FIG. 4 is an end view of a complementary constituent member of the valveshowing an abutment structure for preloading the control disc andfacilitating reverse operation;

FIG. 5 is a fragmentary view of the structure of FIG. 2 showing thecontrol disc in its closed position to prevent fluid from flowingthrough the valve;

FIG. 6 is a fragmentary view similar to that of FIG. 5 showing thecontrol disc in its open position to permit the passage of fluid throughthe valve;

FIG. 7 is a perspective view of an alternative control valve inaccordance with the invention;

FIG. 8A is a cross-sectional view of the valve of FIG. 7 with theconstituent parts of the valve separated to show theirinter-relationship with greater clarity; and

FIG. 8B is a cross-sectional view of an alternative valve which is animprovement over the valve of FIG. 8A, with its constituent partsseparated and including an intermediate, segmented annular rib forenhanced flexure control.

DETAILED DESCRIPTION

With reference to the drawings, illustrative control valves 10, 100, and100', all in accordance with the invention, are shown in respectiveFIGS. 1, 8A and 8B.

The control valve 10 of FIG. 1 is formed by complementary body members20 and 30 with flow channels 21 and 31 that are controlled by aflexible, elastomeric control disk 40, as shown in the cross-sectionalview of FIG. 2.

The control valve 100 of FIG. 8A is also formed by complementary bodymembers, which are respectively designated 200 and 300. The lattercontain respective flow channels 210 and 310 that are controlled by aflexible, elastomeric control disk 400.

The control valve 100' of FIG. 8B is similar to that of FIG. 8A. It hascomplementary body members 200 and 300', with respective flow channels210 and 310'. The same elastomeric control disk 400 that is used for thevalve of FIG. 8A is also used in the valve of FIG. 8B.

Considering first the details of the control valve 10 of FIG. 1, itscontrol disk 40 is positioned within the flow channel 21, which servesas a control channel, in the body member 20. By contrast with the priorart, the disk 40 has substantially the same circumferential diameter asthe channel 21. It is to be noted that the channel 21 in the body member20 includes two concentric portions, a narrowly constricted portionwhich extends away from the mating body member 30, and diverges into awider portion towards the body member 30. The disk 40 has substantiallythe same circumferential diameter as the channel 21 at its widerportion, as clearly demonstrated in FIG. 2. As a result there issubstantially no lateral movement of the disc 40 with respect to thechannel 21.

As further indicated in FIG. 2, the disc 40 is seated on the flangesurface of a ring seat 22. The ring 22 has a hollow interior with aconvex shoulder 23 to promote secure sealing in accordance with theinvention.

In addition, the ring seat 22 surrounds a base depression 24 containingthe inlet of the channel 21. The base depression 24 further includes aset of radial channels 25 (more particularly shown in FIG. 3) thatinsure that the disc 40 will not be pulled into the inlet of the channel21, and thus produce undesired distortion and distension of the disc 40.Longitudinal channels 26 are included at the periphery of the controlchannel 21 to facilitate reverse flow through the valve 10.

The disc 40 is prebiased to provide initial seating contact against thering 22 by prongs 32 of the member 30. These prongs 32, which areillustrated in end view in FIG. 4, are separated by passageways 33 whichextend to the outlet channel 31.

It is to be noted that the joinder of the complementary portions 20 and30 of the body structure 10 can be made in any convenient way along aninterface 11. For the particular embodiment of FIG. 2, the interface 11includes a sealing ring 13, but it will be understood that such a ringis illustrative only and that a wide variety of sealing techniques maybe used.

As shown in FIG. 5, when a differential pressure exits between thechannels 21 and 31, with the greater pressure at the channel 31, forexample produced by a vacuum applied to the channel 21 in the directionof the arrow A, the disc 40 is drawn away from the prongs 32 into closercontact with the shoulder 23 of the ring seat 22, bringing about thedesired closure of the valve 10 and isolation of the channels 21 and 31.Since the sealing surface of the ring 22 is in the form of a convexshoulder 23 that extends circumferentially about the base depression 24,the desired seal is achieved without any adverse effect because of theinadvertent pressence of dirt or debris on the sealing edge 23. This isby contrast with, for example, the sealing surfaces of prior art devicesin which the presence of dirt and debris will interface with the desiredclosure. In such a case the initial application of sealing pressure doesnot dislodge the debris, but instead traps it between the disc and thesealing surface. In the case of the present invention, however, anydebris on the ring seat tends to be moved away by the appreciable convexcurvature 23 of the ring 22, coupled with the interior void formed bythe base depression 24.

It is to be noted that because of the radial channels 25 in the basedepression 24, the disc 40 cannot be drawn into the inlet channel 21.This avoids the distension of the control disc frequently found in otherdevices, caused by having the disc sucked into a flow channel.

The reverse operation of the valve 10 is illustrated in FIG. 6. When thedifferential pressure that pulls the disc 40 against the shoulder 23 isremoved and the flow is reversed, the disc 40 again is positionedagainst the prongs 32. Flow can now take place in the directionindicated by the arrow B between the ring seat 22 and the edge of thedisc 40 through the auxiliary longitudinal channels 26. Because of thechannels 26, it is not necessary to reduce the diameter of the disc 40below that of the control channel 21 in order to permit the desiredreverse operation.

An alternative control valve 100 in accordance with the invention isillustrated in FIG. 7. As in the case of the control valve 10 of FIG. 1,the valve 100 of FIG. 7 is formed by complementary body members 200 and300 with flow channels 210 and 310 that are controlled by a flexible,elastomeric control disk 400, illustrated in the cross-sectional view ofFIG. 8.

The control disk 400 is positioned within the control channel 210 of thebody member 200. As in the case of the disk 40 of FIG. 2, the disk 400of FIG. 8 has substantially the same circumferential diameter as thechannel 210. In addition the shoulders 201 of the member 200 areprovided with a radius in order to prevent the disk 400 from becomingtrapped between the parts 200 and 300 during assembly of the valve. Ithas been discovered that because of the prebiasing of the disk providedby the prongs 320 of the member 300 there is otherwise a tendency forthe disk 400 to be shifted out of the channel 210 during the assemblyprocedure. The radiusing of the shoulders 201 helps to assure that thedisk 400 will enter and seat properly in the channel 210. In additionthe channel 210 contains a seat 221 of a ring 220 which hassubstantially the same diameter as the disk 400 in its relaxed, unbiasedstate. The seat 221 extends slightly below the shoulders 201. Betweenadjoining ones of the shoulders 201 slots 202 are provided whichfunction in a manner similar to that of the longitudinal channels 26shown in FIG. 3. However, instead of being semicircular, the slots 202of FIG. 8 are quadrilateral with side walls 202s that lie along theradius from the central axis A. In addition each slot 202 has a rearwall 202r that is an arc of a cylinder that is concentric with the axisA. This configuration of the slots has been found desirable tofacilitate construction of the member 220, as well as promote theoperation of the valve. Moreover, it has been found desirable touniformly distribute the slots along the wall of the valve with theslots 202 having the same arc length as the shoulders 201. In theillustrative embodiment of FIG. 8, eight slots are provided and eightshoulders.

Also indicated in FIG. 8 is the extension of the seat 221 below edges ofthe slots 202. This disposition of the slots relative to the seat hasbeen found to further promote the operation of the valve. Additionally,the ring 220 has a base 222 which has a diameter that makes the area ofthe base 222 greater than one-fourth the area of the seat 221. In anillustrative embodiment of the invention the ratio between the diameterof the base 222 and the seat 221 was approximately 3 to 4.

The entry from the base 222 into the channel 210 at the coupling portion205 of the member 200 includes a rounded edge 223. This limits thetendency for the disk 400 to be sucked into the channel 210 at thecoupling 205.

As can be seen for the member 300 of FIG. 8, the biasing prongs 320 areprovided with outwardly sloping buttresses 321 in order to give themsuitable strength. In an illustrative embodiment of the invention theangle of the buttress with respect to the linear inner wall 322 wasapproximately 15°. A similar angle of depression was found appropriatefor the inwardly tapered surface 323 extending from the tip 324 of eachprong 320. A channel 330 is provided between adjoining ones of thewedged-shaped prongs 320. The base of each channel 330 has a roundededge 331 where the channel 310 meets the prong channel 330. A shelf 340that engages the upper surfaces of the shoulders 201 when the parts 200and 300 are assembled includes a ridge 341 of triangular cross-sectionthat is included in order to promote the sealing of the parts 200 and300 together by sonic bonding.

Still another control valve 100' in accordance with the invention isillustrated in FIG. 8B. As in the case of the control valve 100 of FIG.8A, the valve 100' of FIG. 8B is formed by complementary body members.One of the body members 200 is identical with the corresponding bodymember 200 of FIG. 8A. The other body member 300' is a modification ofthe body member 300 of FIG. 8A. In addition, the body member 300'includes a flow channel 310' and a segmented annular ring 350'. The ring350' includes individual segments 351', 352', 353', etc.

The segmented ring 350' functions in connection with the flexible,elastomeric control disk 400 that is positioned at the diverging openingof the control channel 210 in the body member 200.

As in the case of FIG. 8A, biasing prongs 320 engage the disk 400 whenthe parts 200 and 300' are brought together. In addition, the segmentedring 350' is present to prevent the flexible disk 400 from overflexingupwardly when the valve 100' is operated in its open position with theflow into the channel 210 and then outwardly into the channel 310'. Thepresence of the individual segments 351' etc. tends to prevent the disk400 from inadvertently hanging on to any portion of the body member 300'and assure that the disk 400 will return to its closed position whenflow from the channel 210 into the channel 310' is removed. It is to benoted that the individual segments 351' etc. have complementary, slopingbuttresses which diverge from the apex point facing the disk 400 towardsthe base at the interior of the member 300'.

While various aspects of the invention have been set forth by thedrawings and specification, it is to be understood that the foregoingdetailed description is for illustration only and that various changesin parts as well as the substitution of equivalent constituents forthose shown and described may be made without departing from the spiritand scope of the invention as set forth in the appended claims.

What is claimed is:
 1. A flow control device comprising:a housing; acontrol channel in said housing extending to a flow channel; a flexibledisc on a valve seat in said control channel; means for prebiasing saidflexible disc comprising a set of prongs for engaging a central portionof said disc and being separated by passageways that extend to said flowchannel; and a segmented ring surrounding said flow channel to preventsaid flexible disc from overflexing when said device is operated in itsopen position with flow into said control channel and outwardly throughsaid flow channel.
 2. A control device as defined in claim 1 whereineach prong includes a buttress that slopes away from a peak of the prongtowards the base thereof.
 3. A control device as defined in claim 2wherein the buttress has an angle of approximately 15° with respect tothe central axis of said device.
 4. A control device as defined in claim1 wherein said prong includes a portion that slopes away from the peakthereof towards said control channel.
 5. A control device as defined inclaim 1 wherein said housing is in two mating parts, one of whichincludes a ridge at the mating surfaces of said parts to promote thesealing of said device.
 6. A control device as defined in claim 5wherein said device is sealed by ultrasonic bonding and said ridge has atriangular cross-section.
 7. A control device as defined in claim 1wherein one of the channels contains a base that extends to an outletwith a curved shoulder between said outlet and said base to limit thedistortion and distension of said disc during the operation of saidvalve.